1. Technical Field
The present invention relates to data processing systems, and more particular to computer systems and security in such systems which are in compliance with the Trusted Computing Platform Alliance (or TCPA) specification.
2. Description of the Related Art
The Trusted Computing Platform Alliance (TCPA) is a group of computer industry companies formed with a goal of developing hardware and operating system security capabilities. A computing system or platform, such as a personal computer, is provided with built-in security mechanisms so that the PC and computer system and its peripheral devices are kept secure with minimal reliance on a user or administrator. The TCPA published an approved specification, entitled Main Specification, Version 1.1, in July, 2001, which sets forth definitions of subsystem functions for increased trust and security in computing platforms or systems.
The TCPA specification requires the system to measure the POST/BIOS code for the computer system prior to execution of the code. This requires some amount of trusted and protected code to run at initial power on to measure the remaining POST/BIOS code. This trusted code is referred to as the Core Root of Trust for Measurement (or CRTM) and is usually implemented in a bootblock segment of flash ROM in the computer system.
Special precautions must be taken to protect this function and thus to ensure the integrity of the measurement. These precautions usually render field update of the bootblock segment difficult or impossible without replacing the system planar.
Thus, it would be advantageous to implement the TCPA function for a computer system as an add-in feature card. If the TCPA function and protection mechanisms are included in the base system of the personal computer, systems without TCPA functions must endure the penalties of protecting the CRTM. Specifically, the TCPA requirements for protecting the CRTM prevent updating the boot block to accommodate additions or modifications to the base system.
It would be desirable to provide a computer system which is compliant with the TCPA specification as a part of a feature card, and to ensure POST/BIOS execution from the feature card while the TCPA function is enabled. It would also be desirable to permit enabling of TCPA compliant functions by replacing a TCPA feature card rather than an entire system planar.